Self-powered programmable UV optoelectronic logic gates via polarity-reversal photocurrent in a Ga2O3/GaN heterojunction

Abstract

Ultraviolet optoelectronic logic gates are attractive for low-power information processing in secure sensing and communication systems. Here, a self-powered, Ga2O3/GaN heterojunction photodetector (PD) that enables input-controlled reconfigurable ultraviolet (UV) optoelectronic logic gates under zero bias is reported. The built-in electric field of the heterojunction induces photocurrent polarity reversal under 254 and 365 nm illumination, providing the basis for logic-gate reconfiguration. On this basis, two operation modes, termed switch-to-logic (via LED on/off states) and voltage-to-logic (via driving-voltage modulation), are established to implement six representative Boolean logic functions including AND, OR, NAND, NOR, XOR, and XNOR with a single device. The photodetector exhibits zero-bias responsivities (R) of 1.8 mA/W at 254 nm and 1.23 mA/W at 365 nm, together with specific detectivities (D*) above 1×1010 Jones at both wavelengths. Logic switching is achieved by modulating either the illumination states or the driving-voltage windows of two UV light sources without altering the device structure. This work provides a compact and low-power proof-of-concept platform for self-powered UV optoelectronic logic gates and highlights the potential of wide-bandgap heterojunctions for low-power ultraviolet information processing.